WIRELESS TELEGRAPHY.

Press, Volume LXIV, Issue 13104, 1 May 1908, Page 7

WIRELESS TELEGRAPHY.

USED FOR TRANSMITTING PHOTOGRAPHS. United Press Association—By Electrio Telegraph— Copyright. LONDON, April 29."— A Dane named' Kundsen demosnistrated at the Hotel Cecil the utility of a machine for transmititjing photographs by aJiy ttireloss system.

In view of the success of telegraphic photography with wires, tha adaptation, oi wireless telegraphy v> the invention is not surprising. A few nioortbs ago teiegrsLpiu'C photographs were e:saha.ugod very suctotssiuiry between London and Paris, by Proiessor Korn, tie imventor. Tile basis of Professor ivorn's process is the "Daily Mail") the varied resistsimce of a pnatographic lilm to light. As every amateur photograpiier knows, the varying iateasdty ot an exposed iiim permits lighit to go readily through certain parts of it, and witii more or less resistance through otiher parts. Tiho same principle is employ**! to cause rapid suweseive changes of eteetric current on. tihe wire, and thus enable the photograph to be telegraphed. Wieiv the nJm is placed in tlu> revolving gtiai&s drum a very powerful , light, content-rated by means <ri a special lens, penetrated by moans of a trny hole 011 to minute portions oi it._ Tihia light is caught on a prism and is reflected on to a seJenium cell. The telephone wire between thot receiving and traouMnatting 'iuetroments psißses through this solwiiujn wiA. Solenium has t£e peculiar property varying ite oJeotno resistnnoQ aceordiiig to tjue amoimt of light, 'lliiis tlu> j-esistaaco wanes eicoording to tiho iHumirwttion. Tlw darker tiie roflectaon tihe weaker the currerat. Thus causes rapid successive changes of curronit, wMoh are in»sfcan'tily rogistored on. the receiving instrument at the other ond, whot.her fclwA ernd be a hundr<>d or a tiunieand miles away. Professor Koru's recoiver utilises tiies© changing; ourrenrts to reproduce a facsimile picture. An tmexposod photographic film at tho moeiving ond is aJso placed on a cyKndricaJ dram, revolving with a spiral motion. Ligfet is admitted to it througjh a tiny hole. Oorrospoi din*; parts of til© films a-t oithor oml are exposed simultaneously. A tiny bit of aluminium foi] held l>efcween poles of a powerful oteotro-magnet tlirows a deep shadow over the hole of the box oontainin'jz the receiving film, and protects it from tho light. The ourrent causes this foil to move, and to move in. just such a degree aa bo pormit the necessary amount of exposiKre to the film, an amount corresponding to tih<j dogreo of lieiiit in. the part of the transmitting film a± the other end. Thus a negative at on© "ond reproduces a positive at the otfher, and vice versa.